1. Field of the Invention
The invention is concerned with hydrocarbon conversion processes. More particularly it is concerned with a specially activated erionite and its use in the shape selective conversion of a hydrocarbon charge.
2. Discussion of the Prior Art
It is well known in the prior art to crack a hydrocarbon charge by contacting it with a zeolite to which a hydrogenation catalyst has been added, either by impregnation or by ion exchange. For example, U.S. Pat. No. 3,379,640 relates generally to a shape selective hydrocarbon conversion process in which the zeolite must meet three critical criteria. These are that, first, it must have a certain silicon to aluminum ratio, second, there must be no hydrogenation/dehydrogenation metals, etc. on the surface of the crystal and third, any hydrogenation/dehydrogenation component present therein must be within the interior of the crystal and be present to no greater extent than about 1.5 cations in a supercage of metals having hydrogenation/dehydrogenation activity.
U.S. Pat. No. 3,575,846 is concerned with a selective hydrocracking process accomplished in the presence of an erionite catalyst having a low potassium content and combined with a metallic hydrogenation component.
U.S. Pat. No. 3,474,025 discloses the use of a zeolite in shape selective hydrocarbon conversions, the zeolite containing no hydrogenating catalyst. The present catalyst must contain an active component.